Apparatus for and method of making filters



y 1957 H. B. PARMELE APPARATUS FOR AND METHOD OF MAKING FILTERS 3Sheets-Sheet 1 Filed May 2, 1952 idila-ssmlitaif FIG. I.

INVENTOR:

HARRIS B. PARMELE May 28, 1957 H- B. PARMELE APPARATUS FOR AND METHOD OFMAKING FILTERS 3 Sheets-Sheet 2 Filed May 2, 1952 6 HARRIS B P A FQ JQS:

May 28, 1957 PARMELE APPARATUS FOR AND METHOD OF MAKING FILTERS 3Sheets-Sheet 5 Filed May 2, 1952 J B F INVENTOR:

HARRIS B. PARMELE r 05 ATTORNEYS.

llllll'nl' FIG. 9.

United States Patent APPARATUS FOR AND METHOD OF MAKING FILTERS HarrisB. Parmele, Glen Ridge, N. J., assignor to H & V Specialties Co., Inc.,a corporation of Massachusetts, and P. Lorillard Company, a corporationof New Jersey, jointly Application May 2, 1952, Serial No. 285,686

3 Claims. (Cl. 93-11 This invention relates to respiratory filters, andhas particular reference to filter units for tobacco products, such ascigarettes, and to methods and apparatus for making the same, althoughthe invention is not limited thereto.

Numerous types of filters for cigarettes, smoking pipes, cigaretteholders, gas masks, surgical respirators and other devices through whichair is drawn by the user have been used or proposed, but in mostinstances, the cost of manufacture and the eifecti-veness of the filtersleave much to be desired. Particularly in the case of tobacco smokefilters for cigarettes and the like, the effort has been to reduce thequantity of volatile materials, principally tar, en trained in thetobacco smoke. In order to be sufficiently effective to remove asubstantial quantity of tar, the filter had to be made so dense as toincrease the suction to an undesirable degree to draw the smoke throughthe filter and cigarette. Consequently, incomplete filters or filtershaving channels or passages were provided, with the result that thefilter was ineffective to remove more than a small percentage of tarwhich was substantially only that which condensed on the surfacesthrough which the smoke was drawn.

Effective filtering material for removing predetermined quantities oftar and also nicotine from tobacco smoke drawn through a cigarette orother smoking article has been provided, one example being disclosed incopending application Serial No. 260,187, filed December 6, 1951 (nowabandoned), by Harold W. Knudson, disclosing filtering materialcomprising fibrous material, such as cotton, containing a predetermined,uni-form distribution of mineral particles having dimensions approachingthose of the smoke particles to be removed, so as to cooperate with thecotton to remove a predetermined proportion of the smoke particles.Notwithstanding the pronounced. effectiveness of this filteringmaterial, its advantage in a cigarette filter unit still depends onuniform density throughout the cross-sectional area of the filter unitwithout any channels or other passages permitting the smoke toshortcircuit the filtering material. The same requirements obtain forother filter units.

In accordance with the present invention, a respirator type of filterunit and a method and apparatus for making the same are provided,whereby smoking articles or other respirator products embodying orcontaining the filter I 2,793,572 Patented May 28, 1957 are interleavedin such a way that the crepe paper layers, each supporting a cottonlayer, are laid one upon the other and the sandwich thus formed issupported on the nethermost crepe paper layer so that the upper surfaceof the sandwich layer is a cotton layer. This sandwich-like sheet is fedto a plug-making machine while carried on the nethermost layer of crepepaper, but just before entering the machine, the nethermost layer ofcrepe paper is stripped therefrom, so that the upper and lower layers ofthe sheet are cotton. Narrow strips are severed transvcrsely from thiscomposite sheet and fed endwise to a conical forming die, but beforereaching the die, the strip is creased off-center lengthwise, so as tothen fold unevenly upon itself in the conical forming die, i. e.,because of the off-center crease, one leg of the infolded strip is widerthan the other, so that the edges thereof do not register. When rolledinto generally J-shaped contour in the forming die, the non-registeringedges of the strip do not leave a passage at the core and, with the aidof cottonto-cotton contact at that point, the resulting plug is ofuniform cross-sectional density. The rope-like strip is then Wrapped inpaper and severed into shorter lengths, which are then incorporated in acigarette, used as a cartridge for smoking pipes, cigarette holders orother smoking articles, or as cartridges for gas masks, surgicalrespirators, and the like.

it will be seen that the filter unit and the method and apparatus ofmaking the same provide a filter unit of uni- 1 form density and draw,not-withstanding the numbers that may be manufactured.

For a more complete understanding of the invention, reference may be hadto the accompanying drawings, in which:

Figure 1 is an elevation of apparatus for laminating three sets of paperoverlaid with a web of fibrous material, such as cotton;

Fig. 2 is a transverse section as seen along the line 2 of Fig. 1,showing the laminate formed in Fig. 1, and comprising three alternatelayers of paper and cotton 'with the entire sandwich-like laminatesupported on the lowermost paper layer;

Fig. 3 is an elevation of the mechanism for feeding the laminate orsandwich of three alternate layers each of cotton and paper throughsuccessive processing stagesand showing the edge-trimming mechanism,intermittent feeding mechanism, mechanism for stripping the lowermostsheet of paper from the sandwich or laminate, and the mechanism forsevering the sheet transversely .into long,

- narrow strips;

Fig. 4 is a schematic plan view of the mechanism of Fig. 3 with theaddition of conical forming mechanism for shaping the long, narrowstrips into a rope-like shape,

wrapping the same and severing it into filter units;

unit are uniform in density and draw to afford the same Fig. 5illustrates the conical forming die of Fig. 4 as it appears on acommercial machine as modified to embody the present invention;

Fig. 6 is an elevation thereof as seen along the line 6-6 of Fig. 5;Fig; 7 is a transverse section through the strip creasing roll and thecarrier tape for the strip as seen along the line 7-7 of Fig. 6 andshowing the off-center relation between the creasing roll and thelaminated strip; Fig. 8 is a transverse section through the formingdieas seen along the line 8-8 of Fig. 6;

Fig. 9 is a transverse section through the grooved pressing rollerconstituting part of the forming mechanism as seen along the line 9-9 ofFig. 6;

' Figs. 10A, 10B and 10C are cross-sections through theilaminated stripin successive stages ofmits formation into the rope, and shows theconvolutions of alternate layers of paper and cotton and the result ofthe cottonto-cotton contact at the center or core without channels andthe off-center creasing of the strip preceding its entry into theconical forming die; and

Fig. 11 illustrates in perspective form a stationary type of stripcreasing or folding device.

Referring to Figs. 1 and 2 of the drawings, the cot ton or other fibrousmaterial C with or without admixture of the mineral particles accordingto the aforementioned Knudson application, is laid uniformly as a thinbut continuous web upon a sheet of paper P, such as crepe paper whosecreases or crepe folds extend transversely thereof. The cotton web maybe conveniently supplied by a commercial carding machine in a widthsomewhat narrower than the width of the crepe paper sheet P, so thatabout a half inch margin of paper extends beyond the lateral edges ofthe cotton web C, as shown in Fig. 2.

In the preferred filter unit of this invention, three layers of cottonand three layers of paper comprise the starting laminate or sandwich andare initially interleaved from three primary supply rolls 10, 11 and 12,rolls 11 and 12 each comprising one long sheet of crepe paper P overlaidby one layer of cotton C, and roll '10 comprising one long sheet ofstrong paper P, such as kraft paper, overload by one layer of cotton C.Layer P also may be crepe paper if desired.

The three primary supply rolls 10, 11 and 12 are simultaneously unrolledwith the unrolled portions of each overlying the unrolled portion of theothers in the manner shown in Fig. 1, so as to form the laminate orsandwich S comprising three alterenate layers each of paper and cotton,with the nethermost layer being paper and the topmost layer beingcotton, as is shown especially in Fig. 2.

The primary supply rolls 10, 11 and 12 are mounted on mandrelsjournalled in a suitable frame, not shown. A driven endless beltconveyor 13 may support the laminate or sandwich S and may drive it andthus 'unroll rolls 10, 11 and 12 by frictional contact therewith, withthe laminate or sandwich S. In this way, the separate twolayer stripsare unrolled from the primary supply rolls 10, 11 and 12 upon a mainsupply roll 14 in step with each other and roll 14, so that the cotton Cand the paper P are not materially strained or stretched. The mainsupply roll 14 may be driven if required. Suitable mechanism accordingwith Fig. 1 and performing the equivalent function is disclosed by AivazPatent No. 1,856,- 823, dated May 3, 1932.

Main supply roll 14 is transferred from storage or from the machine ofFig. 1 to the machine of Fig. 3 for unrolling onto table 15 thereof.Alternatively, the 1aminate or sandwich S may be fed by conveyer 13directly to the horizontal table 15 of Fig. 3. Assuming the transfer ofthe storage roll 14 to the machine of Fig. 3, the former is unwoundflatwise on the table 15 in any suitable way, as by driving its mandrelfrom an intermittent drive mechanism including a source of power such asthe electric motor 16 shown in Fig. 3, whereby the feed of the laminateor sandwich S is synchronized with the intermittent plug-making machineto be described. The unwinding of the roll 14 is so regulated as tomaintain a uniform linear rate of movement of the sandwich or laminate Sover the table 15. One example of a convenient mode of accomplishinguniform unrolling of a large storage roll, such as 14, is disclosed inAivaz Pattent No. 1,993,728, dated March 12, 1935.

As the laminate or sandwich S is advanced over the table 15, the marginsof crepe paper extending beyond the lateral edges of the three webs ofcotton C are trimmed ff in any suitable manner as by rotating knives 17,driven by belt or chain 18 from the mandrel of roll 14 or otherwise inthe manner shown in Figs. 3 and 4. Accordingly, the sandwich or laminateS comprises alternate layers of paper P and cotton C of uniform width.The edge-trimmed sandwich S is engaged by a driving roll 19, driven bychain or belt 20, which aids in drawing the sandwich S through theedge-trimming knives 17 and in advancing the sandwich S along the table15, this driving roll being positioned just beyond the edge-trimmingknives 17 as shown in Figs. 3 and 4.

Positioned just beyond the driving roll 19 and 1ocated in a slot in thetable 15, is idler roll 21 over which the nethermost layer P of papermoves downwardly and is thus separated from the lower cotton layer whichnow takes the place of the separated paper layer P by which the sandwichS was theretofore supported on the table 15. The separated paper layer Pis drawn onto takeup roll 22 suitably driven by a belt or chain 23 atthe proper peripheral speed .to obtain uniform movement of the sandwich5 across the table 15 and take-up roll 22 aids in that movement.Thereupon the sandwich or laminate 5 comprises two layers of paper P andthree layers of cotton C with the upper, lower and center layers beingcotton interleaved by the two remaining layers of paper.

From this point, the five-layer sandwich or laminate S resting ontransverse platform 24 is advanced intermittently by reciprocatingpushers 25 actuated by oscillating shaft 26 preferably driven andconstructed in the manner shown in Ruau Patent No. 2,145,528 whichgenerally illustrates a suitable commercial machine for the manufactureof filter plugs or wads for cigarettes and which has been modified toembody the present invention to manufacture the novel cigarette filterunits or filter units for other respiratory purposes according to thisinvention. Details of the plug-making machinery utilized in part formaking the filter units of this invention may be had upon reference tosaid Ruau patent,

except in so far as the mechanism thereof has been modified in themanner to be described. Only so much of the mechanism of the Ruau patentis disclosed herein as is necessary to an understanding of the presentinvention.

The pushers 25 shown in Fig. 3, advance the five-layer laminate sandwichS beneath a reciprocating knife 27 which severs it transversely intonarrow strips 28 which may be on the order of 1 /2 inches in width and26 inches in length, for example. The severed strips 28 lodge in achannel 29 in which they are advanced endwise by reciprocating grippingmeans shown in said Ruau patent to the belt type conveyor shown in Fig.6, and comprising an endless belt 30 running over a pair of rollers 31journalled in a horizontal plane so as to provide a horizontal conveyingsurface between them. The belt 30 also passes over a series of rollers32, one of which is driven to drive the belt 30 in the proper directionfrom right to left, as seen in Fig. 6.

Positioned above the right-hand or infeed end of the belt 30 as seen inFig. 6, is a feed roller 32' which is driven in the direction ofmovement and peripheral speed by and in accordance with the linear speedof the belt 30 and presses the laminated strip 28 against the belt 30for advancement thereby to the left, as seen in Figs. 5 and 6.

Immediately following feed roller 32 and also driven by the belt 30through the laminated strip 28 is the offcenter creasing or foldingroller 33, whose center line is displaced laterally with respect to thelongitudinal center line of the laminate strip 28 by approximately 4inch, as is shown particularly in Figs. 3 and 7. By reason of itsoff-center position with respect to the strip 28, the rounded peripheryof folding or creasing roller 33 folds or creases the strip 28uneven-1y, lengthwise, i. e., the left-hand portion of the strip 28 asseen in cross-section in Figs. 7, 8 and 10A, is longer transversely thanis the right-hand portion thereof. Hence, as the edges of the strip 28rise in response to the folding and creasing .action of the roller 33,the left-hand edge rises higher than the right-hand edge so that thestrip 28 has the uneven trough-shaped cross-section shown in Figs. 7 and10A. Thus, if the two sides of the strip 28 are folded fiatwise uponeach other, the lateral edges would not be in registry as is shown inFig. 10B.

Positioned at each side of the roller 33 are channelshaped guides 34which are upturned to accommodate and aid the tendency of the edges ofthe strip 28 to turn upwardly in the manner described. To compensate forthe longer left-hand side of the strip, the left-hand guide 34 is longerand extends further from the center line of the feed belt 30 as islikewise shown in Fig. 7. Conversely, the right-hand guide 34 is shorterand lies somewhat more closely to the center line of the belt 30 toaccommodate the shorter half of the strip 28 as seen in cross-section.

As the feed belt 30 carries the strip 28 through the guides 34, itenters the conical forming die 35 at a time when the lateral edges ofthe strip 28 have been lifted to shape it into a reversed J-shapedcross-section with the lefthand leg thereof longer than the right-handleg thereof for the reasons mentioned. Accordingly, as the J-foldedlaminated strip 28 enters the conical forming die 35, which is acontinuation of the guides 34, the offset edges are curled downwardlyupon one side of the center portion which then takes the convolutedshape shown in Fig. 100.

As the folding strip 28 advances, the concavity of the surface of theroller 36 which cooperates with the concave upper roller 37, the belt 30is warped into a U-shape to aid in circumferentially confining the strip28 into the rope-like contour 28' shown in Fig. 9. Accordingly, thestrip 28 is confined circumferentially into a generally circularcross-section with the cotton-to-cotton contact between the originalcotton upper surface and the original cotton lower surface of the strip28 and between the same cotton surfaces folded upon each other, therebyprecluding or closing all passages which tend to form, and aided by themisalignment of the edges of the strip 28 so that uniform densityresults.

The rope emerging from between guides 38 is delivered immediately to thewrapping station where a strip 39 of cigarette paper, for example, isconcurrently fed from reel 40 shown in Fig. 4 and wherein the rope 28'is wrapped in the manner described in said Ruau patent, and the seamheat-sealed with glue or cement at 41.

The successive strips 28 are aligned end-to-end as they are shaped intothe circular cross-section shown in Figs. 9 and 10C, and are wrapped inthe paper from reel 40 so that a continuous wrapped rod 42 emerges fromthe machine to be severed into approximate 2% inch lengths 43 by theflying knife 44 in the manner shown in said Ruau patent. The cylindricallengths 43 having the transverse joint formed at the juncture ofsuccessive strips are culled out by removal of every tenth, and theremaining lengths are then subdivided into shorter lengths, incorporatedin the end of a cigarette in a cigarette-making machine to become partof the cigarette.

The off-center folding or creasing of the strip 28 to achieve the unevenfolding of the edges upon each other may be eifected by other means thanthe roller shown in Fig. 7. For example, the stationary vertical bladeshown in Fig. 11 will perform the folding function of the roller 33 orother equivalent mechanism.

In its passage through the conical forming die 38, the trough-shaped butunevenly-folded strip 28 assumes convolutions which delineate a shapesomewhat like a pear with the narrow end continued into a curve, andclose variants thereof. In any event, the cotton-to-cotton contacttogether with the misalignment of the lateral edges preclude theformation of channels or passages through which the smoke or othergaseous material may shortcircuit the filter material and thus remainuntreated.

Although the off-center folding of the laminate strip to misalign theopposite edges thereof upon formation into a rope is preferred,foldingof the strip along its center line into U-shaped cross-section inthe manner effected by the machine of said Ruau patent neverthelessstill provides filter units which are satisfactory for many purposes,because of the cotton-to-cotton contact afforded by the greater numberof cotton layers as compared to the one less number of paper layers, e.g., two-to-one, respectively, to morethan three-totwo, respectively, e.g., five-to-four, respectively, depending upon requirements.

Similar mechanisms may be provided for forming filter units of differentdimensions according to the method of this invention for use as gas maskor surgical respirator filter cartridges and the like, as well as filtercartridges for cigarette holders, smoking pipes, and the like.

The term cotton as used herein means any suitable natural or synthetictextile fibers capable of being formed into a thin, pervious web, andthe term paper as. used herein means any suitable sheet material havingthe properties described herein and generally substantially imperviousto the passage of gases and vapors.

Although preferred embodiments of the filter unit and method andapparatus for making the same have been illustrated and describedherein, it is to be understood that the invention is not limitedthereto, but is susceptible to changes in form and detail within thescope of the appended claims.

I claim:

1. The method of making filter units, which comprises alternatelyinterleaving a plurality of layers of pervious fibrous material with oneless layer of substantially impervious sheet material to form amultiple-ply laminate with layers of said fibrous material forming itsopposite, outer surfaces, longitudinally folding an elongated strip ofsaid laminate into a trough shape with the fibrous material on theinside and the outside of said troughshaped strip, circumferentiallyconfining the trough-shaped strip to form a rope of substantiallycircular cross-section having an outer surface layer of said fibrousmaterial, wrapping the rope in sheet material to form a tubular covertherefor, and transversely severing the covered rope into cylindricalplugs for use as filter units.

2. The method of making filter units, which comprises laminating aplurality of sets of a pervious web of fibrous material carried on asheet of substantially impervious sheet material to form a multiple-plylaminate consisting of an equal number of said webs and sheets supportedon the nethermost sheet, stripping the nethermost sheet from thelaminate to provide a laminate comprising top and bottom webs of fibrousmaterial and at least one interleaved sheet, longitudinally folding anelongated strip of said last-named laminate into a trough shape,circumferentially confining the trough-shaped strip to form a rope ofsubstantially circular cross-section, wrapping the rope in sheetmaterial to form a tubular cover therefor, and transversely severing thecovered rope into cylindrical plugs for use as filter units.

3. In apparatus for making filter units, the combination of a source ofa plurality of sets of a pervious web of fibrous material carried on asheet of substantially impervious sheet material, means for lapping aplurality of said sets to form a multiple-ply laminate consisting of anequal number of said webs and sheets supported on the nethermost sheet,means for stripping the nethermost sheet from the laminate to provide alaminate com prising top and bottom webs of fibrous material and atleast one interleaved sheet, means for longitudinally folding anelongated strip of said last-named laminate into a trough shape, meansfor circumferentially confining the trough-shaped strip to form a ropeof substantially circular cross-section, means for wrapping the rope insheet material to form a tubular cover therefor, and means fortransversely severing the covered rope into cylindrical plugs for use asfilter units.

(References on following page) 7 References Cited :in-the file of :thispatent UNITED STATES PATENTS 8 Alley May 23, 1939 Davidson 'July 4, 1939Davidson Nov. 12, 1940 Sebox et a1 Feb. 26, 1952 FOREIGN PATENTSNetherlands Aug. 16, 1933 Great Britain Oct. 28, 1935 MW M W."

